Google's Project Ara modular smartphone is coming to developers soon, but it's lost a key part of its customization vision along the way.

Developers will be able to get their hands on an early release version of Ara by the end of this year, to begin building custom hardware modules for the device, Google announced at its I/O conference Friday. The modules will allow users to customize their phones with hardware like cameras, speakers, and even a rear-facing display.

Ara's initial philosophy was to serve as a wholly modular smartphone, which would allow users to customize all of the phone's components, including its processor, battery, network connectivity, and screen. Now, many of those components will be integrated into the Ara "frame," which will still retain space for some customization.

This means that users won't be able to buy one frame that acts solely as a network hub between modules and then continually upgrade it with new processors, network chips, and more.

But the process of setting up and maintaining an Ara phone will likely be easier for everyday users who won't have to worry about accidentally leaving their cellular data connection at home by removing a network module.

Last year, Google announced that its Project Ara smartphone pilot in Puerto Rico had ended as the company was re-evaluating what it wanted to do with the initiative. This revamped frame appears to be the result. It still stays true to the idea of Ara as a heavily customizable phone -- the frame has room for up to six custom modules -- but simplifies the product.

Consolidating all of the phone components of an Ara device into the frame reduces its customizability, but provides several benefits, like giving users a slim, integrated phone experience with room for them to add specific functionality they can't get from general-purpose consumer phones.

Developers can apply to be part of the Project Ara beta here. Google asks that all applicants describe what they want to do with one of the test units, meaning people who just want to take one of the devices for a spin will likely be turned away.

Looking forward, Google plans to release other Ara frames, and those won't necessarily resemble smartphones. We might even see an Ara tablet on the horizon.

Ara isn't the only Android phone banking on customization. LG's new G5 lets users swap out the bottom of the phone to get different functionality, but it doesn't have nearly as many slots for enhancement as Ara does.